Nucleotide-Binding Oligomerization Domain 1 (NOD1) Agonists Prevent SARS-CoV-2 Infection in Human Lung Epithelial Cells through Harnessing the Innate Immune Response.

The lung is prone to infections from respiratory viruses such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). A challenge in combating these infections is the difficulty in targeting antiviral activity directly at the lung mucosal tract. Boosting the capability of the respiratory mucosa to trigger a potent immune response at the onset of infection could serve as a potential strategy for managing respiratory infections. This study focused on screening immunomodulators to enhance innate immune response in lung epithelial and immune cell models. Through testing various subfamilies and pathways of pattern recognition receptors (PRRs), the nucleotide-binding and oligomerization domain (NOD)-like receptor (NLR) family was found to selectively activate innate immunity in lung epithelial cells. Activation of NOD1 and dual NOD1/2 by the agonists TriDAP and M-TriDAP, respectively, increased the number of IL-8+ cells by engaging the NF-κB and interferon response pathways. Lung epithelial cells showed a stronger response to NOD1 and dual NOD1/2 agonists compared to control. Interestingly, a less-pronounced response to NOD1 agonists was noted in PBMCs, indicating a tissue-specific effect of NOD1 in lung epithelial cells without inducing widespread systemic activation. The specificity of the NOD agonist pathway was confirmed through gene silencing of NOD1 (siRNA) and selective NOD1 and dual NOD1/2 inhibitors in lung epithelial cells. Ultimately, activation induced by NOD1 and dual NOD1/2 agonists created an antiviral environment that hindered SARS-CoV-2 replication in vitro in lung epithelial cells.

EBUS-TBNA for mediastinal staging of centrally located T1N0M0 non-small cell lung cancer clinically staged with PET/CT.

BACKGROUND AND OBJECTIVE: To evaluate the diagnostic accuracy and clinical usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for mediastinal staging of centrally located T1N0M0 non-small cell lung cancer (NSCLC) clinically staged with positron emission tomography/computed tomography (PET/CT). METHODS: We conducted a study that included patients with centrally located T1N0M0 NSCLC, clinically staged with PET/CT who underwent EBUS-TBNA for mediastinal staging. Patients with negative EBUS-TBNA underwent mediastinoscopy, video-assisted mediastinoscopic lymphadenectomy (VAMLA) and/or lung resection with systematic nodal dissection, that were considered the gold standard. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), overall accuracy of EBUS-TBNA for diagnosing mediastinal metastases (N2 disease) and the number needed to treat (NNT: number of patients needed to undergo EBUS-TBNA to avoid a case of pathologic N2 disease after resection) were calculated. RESULTS: One-hundred eighteen patients were included. EBUS-TBNA proved N2 disease in four patients. In the remaining 114 patients who underwent mediastinoscopy, VAMLA and/or resection there were two cases of N2 (N2 prevalence 5.1%). The sensitivity, specificity, NPV, PPV and overall accuracy for diagnosing mediastinal metastases (N2 disease) were of 66%, 100%, 98%, 100% and 98%, respectively. The NNT was 31 (95% CI: 15-119). CONCLUSION: EBUS-TBNA in patients with central clinically staged T1N0M0 NSCLC presents a good diagnostic accuracy for mediastinal staging, even in a population with low prevalence of N2 disease. Therefore, its indication should be considered in the management of even these early lung cancers.

Usefulness of Routine Bronchial Aspirate of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration.

INTRODUCTION: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is commonly used for the study of intrathoracic lymphadenopathy and centrally tumours but no report has discussed the contribution of routine cytological and microbiological BA during the procedure. The aim of the study was to analyse the diagnostic yield of BA during EBUS, and to determine the potential cost reduction. METHODS: A prospective study of cytological and microbiological BA collected during EBUS-TBNA was conducted between January 2021 and June 2022. Demographic data, indication, previous BA bronchoscopy or EBUS diagnosis were recorded. The main variable tested was the number of patients in which the result of the BA obtained through EBUS-TBNA determined a change in the diagnosis. RESULTS: A total of 450 (70.9% male) patients were included. BA cytology showed abnormal cells in 33 (7.3%) of patients, and only 1 case (0.2%) provided a previously unknown diagnosis. All these cases were patients with suspected malignancy. BA microbiological samples found germens in 30 (6.7%) patients but only in 5 cases (1.1%) found microbiological specimens not detected in previous bronchoscopy. None of them received antibiotics and evolved correctly. The potential total cost reduction during the study period at our centre if routine BA was deleted would be 21,937.50€ for routinely combined study. CONCLUSIONS: The low diagnostic yield of cytological and microbiological bronchial aspirate in EBUS-TBNA supports the idea of not performing routine BA. Although the potential for cost savings in caring for an individual patient is modest, many centres routinely perform BA, so the potential savings could be significant.

Incidence and Risk Factors for Infectious Complications of EBUS-TBNA: Prospective Multicenter Study.

The aim of our study was to describe the incidence of infectious complications of endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) and to analyze the potential risk factors in a prospective cohort of patients. METHODS: We conducted a prospective multicenter study, with all consecutive patients referred for an EBUS-TBNA with patients at risk of developing an infectious complication (considering>10 nodal samplings, known immunosuppression, bronchial colonization and cavitated or necrotic lesions) and a second group without any risk factor. RESULTS: Three hundred seventy patients were included: 245 with risk factors and 125 without risk factors (as the control group). Overall, 15 patients (4.05%) presented an acute infectious complication: fourteen in cases (5.7%) and 1 in controls (0.8%). Of these, 4 patients presented pneumonia, 1 mediastinitis, 4 obstructive pneumonitis and 6 mild complications (respiratory tract infection that resolved with antibiotic). Also 7 (1.9%) patients had self-limited fever. One-month follow-up showed 1 mediastinitis at sixteenth day post-EBUS, which required surgical treatment, and 3 pneumonias and 3 respiratory tract infections at nineteenth day (1.9%). All patients had a good evolution and there were no deaths related with infectious complication. We observed an increased risk of complication in patients with risk factors and in patients with necrosis (p=0.018). CONCLUSIONS: The incidence of infectious complications in a subgroup of patients with risk factors was higher than in patients without risk factors. Nevertheless, it remains low, and no fatal complication occurred, which reinforces the idea that EBUS-TBNA is a safe technique for the assessment of the mediastinum. Necrotic lesions are a risk factor of post-EBUS infection, and their puncture should be avoided.

Bronchoscopy in Critically Ill COVID-19 Patients: Findings, Microbiological Profile, and Coinfection.

BACKGROUND: Bronchoscopy is a widely use technique in critically ill patients. Nosocomial coinfections are a cause of morbidity and mortality in intensive care units. OBJECTIVES: Our aim was to describe bronchoscopy findings and analyze microbiological profile and probably coinfection through bronchial aspirate (BA) samples in patients with coronavirus disease 2019 pneumonia requiring intensive care unit admission. METHODS: Retrospective observational study analyzing the BA samples collected from intubated patients with coronavirus disease 2019 in a referral Hospital (Spain). RESULTS: One hundred fifty-five consecutive BA samples were collected from 75 patients. Ninety (58%) were positive cultures for different microorganisms, 11 (7.1%) were polymicrobial, and 37 (23.7%) contained resistant microorganisms. There was a statistically significant association between increased days of orotracheal intubation and positive BA (18.9 vs. 10.9 d, P<0.01), polymicrobial infection (22.11 vs. 13.54, P<0.01) and isolation of resistant microorganisms (18.88 vs. 10.94, P<0.01). In 88% of the cases a new antibiotic or change in antibiotic treatment was made. CONCLUSION: Bronchoscopy in critically ill patient was safe and could be useful to manage these patients and conduct the microbiological study, that seems to be higher and different than in nonepidemic periods. The longer the intubation period, the greater the probability of coinfection, isolation of resistant microorganisms and polymicrobial infection.

Detection of Autoantibodies in Bronchoalveolar Lavage in Patients with Diffuse Interstitial Lung Disease. / Detección de autoanticuerpos en el lavado broncoalveolar en pacientes con enfermedad pulmonar intersticial difusa.

INTRODUCTION: Serum autoantibodies support the diagnosis of interstitial lung disease (ILD) related to systemic autoimmune diseases (SAD-ILD). Nevertheless, their presence in the bronchoalveolar lavage (BAL) has not been explored. OBJECTIVES: To demonstrate the presence of autoantibodies in the BAL of ILD patients at onset of clinical evaluation, its relation with serum autoantibodies and to analyze clinical features of patients with autoantibodies in BAL. METHODS: Autoantibodies against extractable nuclear antigens (ENAs) were analyzed by immunoblot in the BAL of 155 patient with suspected diagnosis of ILD and 10 controls. RESULTS: Seven ENAs were detected in the BAL of 19 patients (Anti-Ro52, Anti-Ro60, CENP-B, Anti-La, Jo-1, Sm/RNP and Anti-SL70). The most frequent ENA was anti-Ro52 (13 patients; 68,4% of positives ones). Seven patients presented more than one ENAs. Fourteen were diagnosed of SAD-ILD, 3 of interstitial pneumonia with autoimmune features, one of non-specific idiopathic pneumonia and other of silicosis. In 10 cases (52%) IgA autoantibodies were also detected. The autoantibodies observed in BAL were also detected in the serum of 17 patients (90%). There were no significant clinical differences with the patients with SAD-ILD or interstitial pneumonia with autoimmune features with patients with negative BAL. CONCLUSION: The study of ENAs in BAL is feasible and can be a useful tool in the ILD initial algorithm, specifically sustaining the suspected diagnosis of SAD-ILD.